Families' costs form a considerable part of total costs in bronchiolitis care

Abstract Background and aim The burden of bronchiolitis is remarkable due to high morbidity in infants. The aim of this study was to evaluate bronchiolitis‐associated costs for patients' families and the healthcare system. Methods This retrospective, descriptive study included 136 infants under 12 months of age treated at Tampere University Hospital, Finland, between October 1, 2018 and March 31, 2020, with bronchiolitis as the main diagnosis. The data consists of patient background and medical information and of estimated costs for the families and for the healthcare system. The data were collected from the hospital's electronic patient files and registries and were analyzed with descriptive statistical analyzes using SPSS v. 26 software. Results The total median costs associated with bronchiolitis from the perspective of families and healthcare were €16,205 per patient if intensive care was needed and €2266 per patient treated only on the ward. The median costs for the families were €461 and €244, respectively, and for the healthcare system, they were €15,644 and €2019. Conclusion The majority of the total costs for treatment were due to healthcare costs and only 10% of costs were targeted at families. Bronchiolitis‐associated total median costs were 7.2 times higher and the families' costs were 1.9 times higher if intensive care was needed instead of treatment on the ward only.

and 2016, leading to annual total costs of US$734 million. 8 Earlier studies have shown that healthcare system costs have varied between €1800 and €4000 per one bronchiolitis hospitalization, [9][10][11][12] increasing to roughly €8000-€16,800 when intensive care is needed. 9,13 Moreover, the costs have been shown to be higher for premature infants and prematurity leads to significantly higher healthcare costs during the following 12 months. 14 Although the burden of bronchiolitis is considerable for both families and society, there are only a few studies from their perspectives. According to one German study, total socioeconomic costs were €3700 per hospitalization and the parental cost was €87. 12 According to a Dutch study, 15% should be added to the hospitalrelated costs to cover costs from the perspective of families and society. 15 As these two studies were published nearly two decades ago, up-to-date information on bronchiolitis-associated costs from a wider perspective is needed.
The aim of this retrospective study was to evaluate costs associated with bronchiolitis hospitalization from the perspectives of families and healthcare organizations, that is, the hospital, as well as to separately evaluate the costs for treating infants in PICUs or on wards only.

| METHODS
This was a retrospective chart review describing the cost of bronchiolitis hospitalization in infants treated at Tampere University Hospital (Tays), Finland. Tays provides secondary and tertiary healthcare for~4400 infants under 1 year of age living in Tampere and its surroundings, both in urban and rural areas. The healthcare system in Finland is universal and tax-funded. The copayment for the patients or the families is low, meaning that healthcare services are affordable for all patients. Public or private primary healthcare provides only preventive or outpatient healthcare for children, which means that all patients in this area who need inpatient care are treated in Tays. This study was performed with the permission of the Research Director of the hospital. As the study is based on hospital registers and patients were not contacted, no approval from the ethics committee was required.

| RESULTS
A total of 136 infants under 12 months of age treated between October 1, 2018 and March 31, 2020 for bronchiolitis were included in the study. All patients presented at the ED, except one who was admitted directly to intensive care from a secondary care hospital ( Figure 1). The total number of infants visiting the ED was 135, with 117 being admitted on their primary visit and 7 readmitted later.
Eighteen infants who were not admitted on their primary visit returned for one or more secondary visits and eventually all required inpatient treatment. One of them needed intensive care ( Figure 1).
All infants included in this study were young; the median age was 3.0 months (IQR 1.0-5.0). Most of the patients were boys (53.7%) and the most common number of siblings was one (range 0-6; Table 2). The median LOS on the ward for a primary episode was 2.0 days (0.5-6.5), for a secondary episode it was 3.0 days (range 0.5-8.5), and the median LOS in the PICU was 2.5 days (range 1.0-29.0; Table 2).
The total median costs associated with bronchiolitis hospitalization were €16,205 for those treated in the PICU and €2266 for those treated only in the ward ( Table 3). The median costs for the families were €461 for patients treated in the PICU and €244 for patients treated in the ward ( Age on admission (months) 3.0  increased in our hospital since 2015, which may be partly due to inflation or changes in both internal and external prices, but also perhaps due to a different approach used in the evaluation of costs in the studies. As shown in the present study, the reimbursement is lower than hospitalization costs, which is mostly the result of political decisions. Differences between earlier studies may be explained by differences among healthcare organizations and healthcare financing in countries as well as by different ways of estimating the costs in the studies. However, the results are remarkably different when comparing the costs between the high-income and low-income countries, 19 due to different general price levels. The comparison between low-and high-income countries was beyond the scope in this study, but would be an interesting aim for a new study, to evaluate the differences between bronchiolitis costs all over the world.
Previous studies have found that by following the local or well- patients. 21 According to a Colombian study assessing costeffectiveness in the utilization of "good practice" published in 2019, both readmissions within 10 days and costs were lower when following a bronchiolitis clinical practice guideline. 22 Moreover, a US intervention study including 2929 infants found that after bronchiolitis guideline implementation, the total mean cost per patient was reduced by €148 ($197, 2013); in addition, a reduction of 23% in chest radiographs was observed. 23 In another intervention study of bronchiolitis, guideline implementation by the EDs and urgent care centers proved that albuterol use, chest x-rays, virus testing and costs were reduced after guideline implementation. 24 It is evident from these studies that although the cost related to bronchiolitis treatment is substantial, implementing treatment guidelines may reduce costs in addition to improving the treatment.

| LIMITATIONS
The main limitation of our study was its retrospective nature.
Families' costs were probably underestimated due to the study design; not all the information needed was available from electronic patient files. As an example, the information regarding parents' Another limitation is that the number of patients treated in the PICU was relatively small. Moreover, one of the patients had significantly higher costs than the others due to a rare underlying condition and very expensive treatment needed during an extended hospitalization. To minimize the effect, we used the median value instead of the mean value. In addition, we also verified this in an ad hoc analysis by removing this patient, and the results did not change.

| CONCLUSION
The majority of the bronchiolitis-associated costs were due to healthcare costs both in those treated in the intensive care unit (97%) and for those treated only on the ward (89%

ACKNOWLEDGMENTS
This study was partially supported financially by research funding provided by the Tampere University Hospital. The funder had no role in the study design, collection, analysis, and interpretation of data, writing of the report or in the decision to submit the report for publication.

CONFLICTS OF INTEREST
The authors declare no conflicts of interest.

DATA AVAILABILITY STATEMENT
The anonymous data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.

ETHICAL STATEMENT
This study was approved by the Research Director of the Tampere University Hospital (R19631S). According to Finnish law, neither approval from the Ethics Committee nor informed consent from the subjects and/or their guardians were not required for this retrospective register-based study. This study was carried out in accordance with the Declaration of Helsinki. All patient data were managed and conformed to the European Union's General Data Protection Regulation (GDPR) and the data security legislation of Finland.

TRANSPARENCY STATEMENT
Paula Heikkilä affirms that this manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned have been explained.